**EXHIBIT 31.1**

** **

CERTIFICATIONS

 

I, Sherri C.Oberg, certify that:

 

1. I have reviewedthis quarterly report on Form 10-Q of Acusphere, Inc.;

 

2. Based on myknowledge, this report does not contain any untrue statement of a material factor omit to state a material fact necessary to make the statements made, inlight of the circumstances under which such statements were made, notmisleading with respect to the period covered by this report;

 

3. Based on myknowledge, the financial statements, and other financial information includedin this report, fairly present in all material respects the financialcondition, results of operations and cash flows of the registrant as of, andfor, the periods presented in this report;

 

4. The registrant’sother certifying officers and I are responsible for establishing andmaintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and13d-15(e)) and internal control over financial reporting (as defined inExchange Act Rules 13a-15(f) and 13d-15(f)) for the registrant and wehave:

 

a) Designed such disclosure controls and procedures, or caused suchdisclosure controls and procedures to be designed under our supervision, toensure that material information relating to the registrant, including its consolidatedsubsidiaries, is made known to us by others within those entities, particularlyduring the period in which this report is being prepared;

 

b) Designed such internal control over financial reporting, or causedsuch internal control over financial reporting to be designed under oursupervision, to provide reasonable assurance regarding the reliability offinancial reporting and the preparation of financial statements for externalpurposes in accordance with generally accepted accounting principles;

 

c) Evaluated the effectiveness of the registrant’s disclosure controlsand procedures and presented in this report our conclusions about theeffectiveness of the disclosure controls and procedures, as of the end of theperiod covered by this report based on such evaluation; and

 

d) Disclosed in this report any change in the registrant’s internalcontrol over financial reporting that occurred during the registrant’s mostrecent fiscal quarter (the registrant’s fourth fiscal quarter in the case of anannual report) that has materially affected, or is reasonably likely tomaterially affect, the registrant’s internal control over financial reporting;and

 

5. The registrant’sother certifying officers and I have disclosed, based on our most recentevaluation of internal control over financial reporting, to the registrant’sauditors and the audit committee of the registrant’s board of directors (orpersons performing the equivalent functions):

 

a) All significant deficiencies and material weaknesses in the designor operation of internal control over financial reporting which are reasonablylikely to adversely affect the registrant’s ability to record, process,summarize and report financial information; and

 

b) Any fraud, whether or not material, that involves management orother employees who have a significant role in the registrant’s internalcontrol over financial reporting.

 

 
| Date: August 11, 2008 |                           |
|----------------------------|--------------------------------|
|                       |                           |
|                       | /s/ Sherri C.  Oberg           |
|                       | Sherri C. Oberg                |
|                       | Chief Executive  Officer       |
|                       | (Principal Executive  Officer) |

 

----